Derivatives and Hedge Accounting Activities (Schedule of Offsetting Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	$ 1,319	$ 1,100
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Total derivatives, not subject to a master netting or similar arrangement	5	2
Derivative Liabilities	1,324	1,102
Derivative, Collateral, Right to Reclaim Securities	584	568
Derivative, Collateral, Right to Reclaim Cash	452	402
Net Amounts	283	130
Interest rate | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	100	0
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	28	0
Derivative, Collateral, Right to Reclaim Cash	0	0
Net Amounts	72	0
Commodity | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	394	262
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	73	63
Derivative, Collateral, Right to Reclaim Cash	110	69
Net Amounts	211	130
Commodity | Exchange
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	825	838
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	483	505
Derivative, Collateral, Right to Reclaim Cash	342	333
Net Amounts	0	0
Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	29	12
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Total derivatives, not subject to a master netting or similar arrangement	1	0
Derivative Liabilities	30	12
Derivative, Collateral, Right to Reclaim Securities	4	4
Derivative, Collateral, Right to Reclaim Cash	0	7
Net Amounts	25	1
Virginia Electric and Power Company | Interest rate | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	23	0
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	0	0
Derivative, Collateral, Right to Reclaim Cash	0	0
Net Amounts	23	0
Virginia Electric and Power Company | Commodity | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	6	12
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	4	4
Derivative, Collateral, Right to Reclaim Cash	0	7
Net Amounts	2	1
Dominion Gas Holdings, LLC
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	8	25
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	2	6
Net Amounts	6	19
Dominion Gas Holdings, LLC | Interest rate | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	3	0
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	0	0
Net Amounts	3	0
Dominion Gas Holdings, LLC | Commodity | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	5	25
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	2	6
Net Amounts	$ 3	$ 19